pH值与温度对氧化亚铁硫杆菌氧化Fe2+影响的研究

采用自行采集的氧化亚铁硫杆菌(T f)应用于地浸矿山代替双氧水作氧化剂氧化吸附尾液中的Fe²⁺, 研究了温度、pH 值对其氧化Fe²⁺的影响。研究结果表明, T f 氧化Fe²⁺最适宜的温度为30 ℃, 当温度低于7 ℃或高于50 ℃时, 氧化亚铁硫杆菌氧化Fe²⁺速度很慢;T f 氧化Fe²⁺最适宜的pH 为2.0～2.5 。     

耐冷嗜酸硫杆菌的生长特性和固定化培养

为解决氧化亚铁硫杆菌、嗜铁钩端螺旋菌等中温菌在低温和高酸的吸附尾液中作氧化剂时生长繁殖慢、氧化Fe²⁺速率低等问题,以耐冷嗜酸硫杆菌为研究对象,结合新疆某地浸采铀现场生产实际,对该菌的生长特性、耐酸驯化和固定化培养进行了探索。结果表明,该菌的接种量以10%为宜;当初始Fe²⁺浓度为0.3~0.5 g/L时,细菌仍能较快氧化Fe²⁺;在5~25℃条件下,耐冷嗜酸硫杆菌氧化Fe²⁺的速率均高于氧化亚铁硫杆菌,即耐冷嗜酸硫杆菌更适于溶浸液低温环境;耐冷嗜酸硫杆菌耐酸驯化后能在pH=0.31的培养液中保持较好的氧化活性;从生物陶粒表面电镜图片中可以观察出较厚的生物膜,固定化细菌和游离态细菌协同氧化Fe²⁺的速率是游离态细菌单独氧化的3.4倍。     

闪锌矿的生物氧化与化学氧化对比

研究了氧化亚铁硫杆菌对闪锌矿的生物氧化作用,并与Fe³⁺氧化过程进行了对比。研究表明Fe³⁺比细菌具有更高的氧化效率,但生物氧化的效率更稳定。闪锌矿生物氧化过程中氧化亚铁硫杆菌的生长经历了延迟期、指数期、稳定期和衰退期,有部分细菌吸附到了矿物表面,未发现中间物质单质硫沉淀。而闪锌矿的化学氧化过程中有大量的单质硫沉淀到了矿物表面,说明生物氧化更彻底。     

黄铁矿-微生物体系还原浸出低品位氧化锰矿工艺过程研究

利用黄铁矿和微生物组合浸出低品位氧化锰矿,研究了pH值、矿浆浓度和接菌浓度对低品位氧化锰矿中锰元素浸出的影响。结果表明,在pH＝1.6、矿浆浓度15%和接菌浓度20%的条件下,锰浸出率达到92.3%。嗜酸氧化亚铁硫杆菌与溶液中的Fe³⁺能够促进黄铁矿发生氧化还原反应,进而强化氧化锰矿中锰元素的浸出。     

高铁离子浓度环境下氧化亚铁硫杆菌的生长行为

对氧化亚铁硫杆菌在高铁离子浓度下的生长情况进行了研究。在初始[Fe2+]=10、30、50、70、90g/L的高铁离子浓度9K培养基中培养氧化亚铁硫杆菌,定时测培养基中的细菌数、pH值及氧化还原电位(Eh)和Fe2+的终浓度,试验得出:[Fe2+]为30g/L时,氧化亚铁硫杆菌的生长最为旺盛,浓度达到9×107个/mL;在接种量为10%、pH值为1.6的情况下,氧化亚铁硫杆菌的Fe2+氧化速率最高,分别达到2.87g/(L.d)和2.67g/(L.d)。     

脱硫微生物氧化亚铁硫杆菌遗传特性的分子生物学试验

利用现代生物学研究方法和手段，对煤系与非煤系氧化亚铁硫杆菌的遗传特性进行了质粒抽提和琼脂糖凝胶电泳等分子生物学水平的基础性探索试验，对于质粒在硫杆菌中普遍存在的观点提出了质疑.研究结果表明，氧化亚铁硫杆菌对Fe²⁺，S等的氧化能力可能只是与拟核染色体DNA有关，而氧化亚铁硫杆菌的遗传物质就是拟核染色体DNA.     

黄铁矿高效培养嗜酸氧化亚铁硫杆菌及过程分析

以黄铁矿为能量来源对嗜酸氧化亚铁硫杆菌的高效培养进行了研究,并针对培养过程中黄铁矿的能量利用进行了分析。研究表明,在黄铁矿浓度10 g/L、接菌浓度15%和pH＝2.0的条件下培养144 h后,嗜酸氧化亚铁硫杆菌细菌浓度达到6.4×10⁸个/mL。在培养嗜酸氧化亚铁硫杆菌过程中单位质量黄铁矿提供的能量约为培养基中单位质量FeSO₄·7H₂O提供能量的34.7倍,通过黄铁矿可以实现对嗜酸氧化亚铁硫杆菌的高效培养。     

较低温度下细菌浸出黄铜矿工艺影响因素研究

以黄铜矿为研究对象，在温度较低的浸出条件下（15℃）采用正交试验的方法考察了矿石粒度、矿浆浓度、酸度、接种量以及起始Fe²⁺浓度对氧化亚铁硫杆菌（T.f菌）摇瓶浸出黄铜矿浸出过程的影响。试验结果表明：初始Fe²⁺浓度对细菌浸铜工艺影响最为显著；在15℃下的最佳浸出工艺条件为初始Fe²⁺浓度为6g/L，酸度控制在pH=2.0，接种量保持在15%，矿浆浓度为15%，矿石粒度为-200目。     

喷淋塔中固定化Acidithiobacillus ferrooxidans对Fe2 的生物氧化特性研究

为了增大嗜酸氧化亚铁硫杆菌细胞密度以提高其对Fe~(2+)的氧化速率,利用泰勒花环填料为载体,在喷淋塔中固定嗜酸氧化亚铁硫杆菌,考察固定化细胞对Fe~(2+)的生物氧化性能。采用扫描电子显微镜对载体表面进行形貌表征,X射线衍射仪和傅里叶红外光谱仪对填料表面沉淀进行成分分析。结果表明:在改良的9 K培养基中,嗜酸氧化亚铁硫杆菌被成功的固定在泰勒花环填料上,并伴有少量黄铵铁矾沉淀,这些沉淀和菌体细胞一起构成了生物反应系统的生物膜。嗜酸氧化亚铁硫杆菌在喷淋塔中完成固定化后,溶液初始pH值和温度是影响氧化速率的主要原因,其优化结果分别为2.25和34℃。在此条件下,整个生物反应系统能长期保持稳定的氧化特性,Fe~(2+)的氧化速率为4.27 g/L/h。     

柠檬酸强化烟气脱硫体系中亚硫酸钙的氧化过程

在鼓泡反应器中对有机酸体系中亚硫酸钙氧化过程进行了研究.研究结果表明,柠檬酸会阻碍亚硫酸钙的氧化,Fe³⁺能够催化氧化亚硫酸钙,体系中Fe³⁺浓度为0.075 mmol/L,其氧化速率是无Fe³⁺氧化速率的1.64倍;当pH=6.5时,亚硫酸钙氧化速率达到最大,为3.35×10^-6mol/(L·s),其氧化速率与亚硫酸钙的浓度和空气流量成正比.     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

2014 second batch of rare earth quota released

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Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.